Friday, August 31, 2007

Evidence builds for timing of estrogen therapy, researcher says

Two studies reported yesterday bolster the case for a "timing hypothesis" in women taking estrogen after menopause.

The papers published in the journal Neurology suggest that estrogen may protect the brain if the hormone is taken within 10 years of menopause. Other observational studies have shown a 20 percent to 40 percent reduction in the risk of developing dementia if estrogen is started shortly after menopause, Dr. JoAnn Manson, chief of preventive medicine at Brigham and Women's Hospital, said in an interview today.

"There is mounting evidence that a woman's age and the time since onset of menopause influence her health outcomes on estrogen, including the risk of heart disease and cognitive decline," she said. "These (Neurology) studies do suggest that premature loss of estrogen tended to have an adverse effect on memory and cognitive function and that taking estrogen after menopause may counter those risks."

One Neurology paper said that women who had their ovaries removed before menopause had a higher risk of developing dementia or other cognitive impairment if they did not take estrogen until age 50. Another paper reported that the risk of Parkinson's disease and tremors was higher in women who had their ovaries removed, but those movement disorders were both less common than mental problems.

Manson was not involved in either study.

She said that because the studies were not randomized clinical trials, they do not provide conclusive evidence. She is working on her own large-scale randomized clinical trial of low-dose estrogen in preventing memory loss and cognitive decline. Called the KEEPS study, it is currently recruiting participants, and will look at recently menopausal women.

The findings reported in Neurology, while not conclusive, may offer reassurance to women considering the hormone for treatment of hot flashes and other symptoms, she said.

"The new research suggests more favorable benefits in younger women, providing reassurance for recently menopausal women who may be considering hormone therapy for the treatment of menopausal symptoms," she said.